Phase Resolved PD pattern in Electric Treeing

Abstract

Condition monitoring of insulation assumes greater significance in the life time of insulation. Condition monitoring through partial discharge (pd) detection is the need to establish a trend in the discharge pattern for a given insulating system over its lifetime. Treeing is one of the principal routes to failure in insulating materials, and its growth is accompanied by pd activity. In this work, a study of the evolution of the phase resolved pd patterns during the various stages of tree growth is undertaken. Electrical pd detection is performed simultaneously with online visual observation of tree growth with a high resolution high speed camera. Epoxy resin specimens with needle-plate electrode geometry are used. A correlation of pd patterns to the tree morphology is established.